I recently ordered a new CD/MP3 Receiver (Kenwood KDC-X659) to replace the very cheap and basic Aiwa I am currently using.

My empeg is getting its constant power directly from the battery's positive terminal, since I had power issues when it was wired through the Honda's harness. I plan to do this with both the empeg and the new Kenwood, as well as send the ground wires from both units to the negative terminal on the battery.

My question is, when I go back into the dash of my 98 Civic, what would be the best way to go about using the negative battery terminals for constant power and ground? Should I merge the wires and run a single wire each (one for power, one for ground, say 12AWG) to the terminals or should I run separate wires for each unit all the way to the terminals?

Any input would be appreciated.

Don't ground to the battery.. Ground to the car's chassis.. Also, it's probably better to ground them to different places, to prevent any common ground issues.

A single 12 awg wire should be enough for both the empeg and the other HU as the empeg doesn't draw much current. Will you be using the internal amp of the other HU?

/Michael

I had a thread on here before about ground loops, which is what I am currently experiencing. There are no chassis grounding points near the dashboard. The suggestions I received in that thread (wish I could find it) lead me to believe that it was alright to ground to the negative terminal on the battery, since that terminal is grounded to the chassis somewhere anyway. Do you think it would be a better idea to simply find the battery's grounding point on the chassis and use that?

Also, from that other thread, I had gathered that grounding different devices to different points on the chassis is one of the causes of ground loops.

Will you be using the internal amp of the other HU?
Yes. I haven't planned for an external amplifier yet. That's a bit beyond both my budget and my ability.

Yes you can run a single wire from your battery to the head units, amps, and any other equipment you might have with out an issue, mind you use an AWG that is appropriate for the power draw if it's just head-units 12-18 AWG is ok. But keep in mind that the shorter the ground wire is the better. Your best bet is to make a ground spot on the car's chassis very near by the head units, under a foot is best.

As for grounding a multi head unit install in different places on the cars chassis never never never you WILL get ground loops and if there's a problem now you'll have to check more wires to see what the problem is.

Seems I was wrong about the ground point issue.. Will have to change my system (even though I don't have any problems right now..)

Technically, neither do I. There is a ground loop, but it is only audible if I pause playback on the empeg and turn up the volume on the CD Receiver. With the Aiwa, the volume goes from 0 to 80; 50 being where the ground loop becomes audible (barely) above "road noise."

Well I would guess that your grounds are on the same sheet or frame metal and are relatively close together and no corrosion on the connections or you've got some equipment that filters ground loops, if not than either your car's metal work was done with much care, you've got one souped up electrical system or you very lucky.

The truth is that all car audio equipment should have the same reference points in the car's electrical system both positive and negative but that tends to be difficult to do with out rewiring.

Does it change as you push harder and or let off the gas pedal? Kind of a high pitch squeal? If so you can try a few things to lessen it more. One by making sure the grounds connections are paint, dirt, and corrosion free. Two solder your connection. Last try to make the ground leads as short as possible.

And I know most people say crimp not solder the connection in a car because of vibrations, but I've never had a problem with solder connections and it has made night and day differences in my car installs.

Yes, it is "alternator whine." The pitch climbs up and down relative to the engine's RPM. Currently, both the empeg and the CD Receiver are grounded through the factory wiring harness.

As for soldering... I'm incapable. And the only person I know who is can't exactly climb around in my little Civic in order to solder the ground wire connection.

As for soldering... I'm incapable.

Soldering connections in your civic isn't the same as assembling a tuner kit. You just melt large quantities of solder and drop it on... A cheap soldering iron will run you about $10 at Radio Shack or your local equivalent.

Matthew

I would guess that I fall under the first possibility. I mount my Cap and Amps to the rear seat mounts, so they are mounted to a larger piece of metal, and make pretty good contact (wire brushed the bolt).